Hi everyone,
I would like to offer a proposal for a much-requested feature in Beam: Stateful processing in a DoFn. Please check out and comment on the proposal at this URL: https://s.apache.org/beam-state This proposal includes user-facing APIs for persistent state and timers. Together, these provide rich capabilities that have been called "per-key workflows", the subject of [BEAM-23]. Note that this proposal has an important prerequisite: a new design for DoFn. The new DoFn is strongly motivated by this design for state and timers, but we should discuss it separately. I will start a separate thread for that. On this email thread, I'd like to try to focus the discussion on state & timers. And of course, please do comment on the particulars in the document. Kenn [BEAM-23] https://issues.apache.org/jira/browse/BEAM-23
